Four certified public accountants at a Japanese unit of the PricewaterhouseCoopers Group were arrested Tuesday for allegedly collaborating with former executives at Kanebo Ltd. to falsify accounting reports.

The special investigation department of the Tokyo District Public Prosecutor's Office also searched the offices of ChuoAoyama PricewaterhouseCoopers in Chiyoda Ward, Tokyo, and the suspects' homes jointly with the Securities and Exchange Surveillance Commission, prosecutors said.

Pursuing criminal responsibility of certified public accountants in connection with window-dressing is unusual, and the arrests have blemished the credibility of those assigned auditing responsibilities, observers say.